Close shave?

[Torqsplit]

I'm in the middle of a suedo-rebuild and plan to mill the head down to bring my static compression up a bit further. Not changing the pistons, so hoping to accomplish my goals w/ smaller quench. CC'ing the head today to make sure where it is now, but would like to get close to 55cc. Anybody have issues w/ valve to piston interference w/ high compression & high lift cams? Any info/experience w/ this is appreciated. Block is Zero-deck, VR-mls head gasket, 7120 head w/ standard size valves, custom forged pistons w/ 22cc dish/valve reliefs. Thanks!

[SilverXJ]

I've never had valve to piston clearance issues. Plenty of room. Its always good to check to be sure though. Easiest and quickest method is using play dough or silly putty on the pistons and rotate the engine over with the head on w/o head gasket. Of course lifters and pushrods. You can use checking valve springs and make some old lifters solid.

[Torqsplit]

Took the head to my machinist and we cc'd it for starting #'s. Its a 7120 head w/ only a mild resurface, we had 60-61cc between all chambers to start. As theres no set amount of milling/cc equation(sort-of, rough estimates are available for more popular engines but not much for ours), we did a .010 skim to see where that put us. re-cc'd and had 58-59cc, HEY! so another .010 got us to 55-56cc and i was happy. .020" total brought this head down ~5cc. The further you mill the more the chamber crowns-in, especially on the plug-side of the chamber, and you start to get greater returns for each 0.001 you shave so didn't want to overshoot. The higher cc chambers were on #2,3 &4 so it makes it tough to balance 'em any closer. Pretty happy w/ this cause thats an easy amount to account for in my setup and dont think .020 will put me in jeopardy of valve-piston interference!